How do I pass parameters from one ViewController to another ( I defined the ViewControllers in a storyboard)? Is there anything similar putExtra in Android, or any Bundle to put values? I need to read some values from first ViewController and pass to another which is going to make POST request.

prepareForSegue:sender: is the preferred way to pass data from one view controller to another when using storyboards. Check the identifier to make sure it's the segue you're interested in, get a pointer to the destination view controller, and set whatever properties you want. It might look like this:

apart from other ways, u can use Protocol and delegate for passing objects from one controller to another.
Lets say u need to pass object resposeData from controller (class) A to B, below are the steps that u can do:

Decalare a Protocol
eg.

@protocol NetworkOperationDelegate

@required

-(void) operationCompleted:(id) responseData tag:(id) tag;

-(void) operationFailed:(id) responseData tag:(id) tag;

@end

Declare a property of type Id in class A, which points to ur delegate class